CWE-1304 Improperly Preserved Integrity of Hardware Configuration State During a Power Save/Restore Operation

The product performs a power save/restore operation, but it does not ensure that the integrity of the configuration state is maintained and/or verified between the beginning and ending of the operation.

• Confidentiality, Integrity: DoS: Instability, DoS: Crash, Exit, or Restart, DoS: Resource Consumption (Other), Gain Privileges or Assume Identity, Bypass Protection Mechanism, Alter Execution Logic, Quality Degradation, Unexpected State, Reduce Maintainability, Reduce Performance, Reduce Reliability — During the power-down process, an attacker with access to the persistent storage may alter the current state to a configuration that could potentially modify privileges, disable protections, and/or cause damage to the hardware. If the IP does not validate the configuration state stored in persistent memory, upon regaining power or becoming operational again, the IP could be compromised through the activation of an unwanted/harmful configuration.

• [Architecture and Design] Inside the IP, incorporate integrity checking on the configuration state via a cryptographic hash. The hash can be protected inside the IP such as by storing it in internal registers which never lose power. Before powering down, the IP performs a hash of the configuration and saves it in these persistent registers. Upon restore, the IP performs a hash of the saved configuration and compares it with the saved hash. If they do not match, then the IP should not trust the configuration. • [Integration] Outside the IP, incorporate integrity checking of the configuration state via a trusted agent. Before powering down, the trusted agent performs a hash of the configuration and saves the hash in persistent storage. Upon restore, the IP requests the trusted agent validate its current configuration. If the configuration hash is invalid, then the IP should not trust the configuration. • [Integration] Outside the IP, incorporate a protected environment that prevents undetected modification of the configuration state by untrusted agents. Before powering down, a trusted agent saves the IP's configuration state in this protected location that only it is privileged to. Upon restore, the trusted agent loads the saved state into the IP.